Unmanned aerial vehicles (UAVs) have become an alternative to manned aircraft in various military and law enforcement applications. Unmanned aerial vehicles eliminate many risks to crew and may be more varied in design, size, and weight than traditional manned aircraft. UAVs may also operate in areas where manned aircraft may not. For example, use of UAVs to perform reconnaissance and engagement missions is increasing as the technology matures. Rapid deployment of UAVs in a variety of situations allows for faster, and often less observable, intelligence gathering. UAVs may also be used by ground forces to gather surveillance information on a target prior to engagement with human or other high value assets.
UAVs may be launched by a variety of systems, including conventional taxiing, vertical lifting off, launching by hand, and ejecting from mechanical or pneumatic systems. Some of these techniques are more advantageous than others in a given environment, such as in confined geographic areas or urban canyons. Aircraft that can take-off in a completely or substantially vertical manner allow for use in areas where runways are nonexistent, but their flight performance may be limited as a result of their design.